commit 7231344f3b6cf47a458a27ebf0cec1f9aeb41456
author Antonio Barone <syntonyze@gmail.com> Wed Dec 21 13:25:26 2022 +0100
committer Antonio Barone <syntonyze@gmail.com> Wed Dec 21 18:03:36 2022 +0100
tree 28be94458bf80e10c17b6ca74172603a54ba53f5
parent baa8e584795b08cbf396e20cf1285f2456eb440e

Bail out when gc.log.lock exists

Check whether a gc.log.lock file exists when running GC, since it might
signal another in-flight GC is happening at the same time.

However, if the gc.log.lock file exists but its age is older than the
configurable GC_LOCK_EXPIRE_SECONDS, then the file is considered stale,
removed and the GC can continue.

Change-Id: I1c6bcaada4c0f464de823169da95196026cb9181

maintenance/git-gc/scripts/utils.sh

diff --git a/maintenance/git-gc/scripts/utils.sh b/maintenance/git-gc/scripts/utils.sh
index 7b3e6ce..d03f7a9 100755
--- a/maintenance/git-gc/scripts/utils.sh
+++ b/maintenance/git-gc/scripts/utils.sh
@@ -7,6 +7,7 @@
 PACK_THREADS=${PACK_THREADS:-""}
 PRUNE_EXPIRE=${PRUNE_EXPIRE:-""}
 PRUNE_PACK_EXPIRE=${PRUNE_PACK_EXPIRE:-""}
+GC_LOCK_EXPIRE_SECONDS=${GC_LOCK_EXPIRE_SECONDS:-"43200"} # 12 hours
 
 function gc_project {
   proj=$1
@@ -39,6 +40,13 @@
 
 function do_gc() {
     proj=$1
+
+    should_continue_GC "$proj" || {
+      status_code=$?
+      err_proj "$proj" "Could not GC $proj ($status_code)."
+      return 1
+    }
+
     [ -z "$PRUNE_PACK_EXPIRE" ] || $GIT config gc.prunePackExpire $PRUNE_PACK_EXPIRE
     [ -z "$PRUNE_EXPIRE" ] || $GIT config gc.pruneExpire $PRUNE_EXPIRE
     [ -z "$PACK_THREADS" ] || $GIT config gc.packThreads $PACK_THREADS
@@ -103,6 +111,31 @@
    echo "$out"
 }
 
+function should_continue_GC() {
+  proj=$1
+  gc_log_lock="gc.log.lock"
+  lockTime=$(find . -maxdepth 1 -name $gc_log_lock -type f | grep -q . && stat -c "%Z" $gc_log_lock)
+
+  if [ -n "$lockTime" ]
+  then
+    log_project "$proj" "'$gc_log_lock' exists with stats: [$(stat $gc_log_lock)]"
+    now=$(date +%s)
+    lockFileAgeSeconds="$((now-lockTime))"
+    if (( lockFileAgeSeconds > GC_LOCK_EXPIRE_SECONDS ))
+    then
+      log_project "$proj" "Consider '$gc_log_lock' stale since its age ($lockFileAgeSeconds secs) is older than the configured threshold ($GC_LOCK_EXPIRE_SECONDS secs). Removing it and and continuing."
+      rm -vf $gc_log_lock
+      # 0 = true
+      return 0
+    else
+      log_project "$proj" "Consider '$gc_log_lock' still relevant since its age ($lockFileAgeSeconds secs) is younger than the configured threshold ($GC_LOCK_EXPIRE_SECONDS secs). Possibly another GC process is still running? Skipping GC for project $proj."
+      # 1 = false
+      return 1
+    fi
+  fi
+
+}
+
 function log_env() {
   log "######## ENVIRONMENT ########"
   log "# JGIT=${JGIT}"
@@ -113,6 +146,7 @@
   log "# PRUNE_EXPIRE=${PRUNE_EXPIRE}"
   log "# PRUNE_PACK_EXPIRE=${PRUNE_PACK_EXPIRE}"
   log "# JAVA_ARGS=${JAVA_ARGS}"
+  log "# GC_LOCK_EXPIRE_SECONDS=${GC_LOCK_EXPIRE_SECONDS}"
   log "############################"
 }